<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
</head>
<body>
    <div id="app">
        <h1>全名:{{fullName}}</h1>
    </div>
    <script>
        // 使用watch来书写获取全名的逻辑,感受watch和computed的区别
        Vue.config.productionTip=false

        const vm=new Vue({
            el:"#app",
            data(){
                return{
                    firstName:"wang",
                    lastName:"zhoangwang",
                    fullName:""
                }
            },
            watch:{
                firstName:{
                    immediate:true,
                    handler(){
this.fullName=this.firstName.toLowerCase()+" "+this.lastName.toLowerCase()
                    }
                },
                lastName:{
                    immediate:true,
                    handler(){
this.fullName=this.firstName.toLowerCase()+" "+this.lastName.toLowerCase()
                    }
                }
            }
        })
    </script>
</body>
</html>